The rules vary from country to country, but in the UK the Health Protection Regulations provide that 'no person may leave the place where they are living without reasonable excuse'
The reasonable excuses are clearly listed and would include going to work where it is not reasonably possible for that person to work, or to provide those services, from the place where they are living.
So recreational flying is illegal if you leave your curtilage. Rotary pilots with a large garden are ok. Flying to work is OK. And if you have a check ride the instructor is legal but you are illegal....